Can someone explain what is exactly a leak current? Which can be some examples during whole cell recordings?
My understanding is shown in the following example:
A tight seal and a whole cell configuration is achieved (as an example, 1G-Ohm). The applied potential is -80 mV.
From Ohm's low (V=IxR), the current value (I) can be calculated as -80 nA. (Note that there is no current through any ion channels).
This -80 nA is the leak current. The negative polarity (-) shows the inward direction. Each applied potential gives corresponding leak current.
Since the leak current comes from the seal between the electrode and the cell, the leak current should be linear to the variation of potentials. Higher value the seal gives, smaller leak current can be observed.
Hope this helpful.
...can it be consideren as a passive current that occur without any manipulation of the membrane potential?